Resist underlayer film composition and patterning process using the same

ABSTRACT

There is disclosed a resist underlayer film composition, wherein the composition contains a polymer obtained by condensation of, at least, one or more compounds represented by the following general formula (1-1) and/or (1-2), and one or more kinds of compounds and/or equivalent bodies thereof represented by the following general formula (2). There can be provided an underlayer film composition, especially for a trilayer resist process, that can form an underlayer film having reduced reflectance, namely, an underlayer film having optimum n-value and k-value, excellent filling-up properties, high pattern-antibending properties, and not causing line fall or wiggling after etching especially in a high aspect line that is thinner than 60 nm, and a patterning process using the same.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a resist underlayer film compositioneffective as an antireflective film composition used for microprocessingin manufacturing of a semiconductor device and the like, and to a resistpatterning process using the resist underlayer film composition suitablefor the exposure to an ultra-violet ray, a KrF excimer laser beam (248nm), an ArF excimer laser beam (193 nm), a F₂ laser beam (157 nm), a Kr₂laser beam (146 nm), an Ar₂ laser beam (126 nm), a soft X-ray (EUV, 13.5nm), an electron beam (EB), an X-ray, and so on.

2. Description of the Related Art

In recent years, as LSI progresses toward a higher integration and afurther acceleration in speed, miniaturization of a pattern rule isbeing requested. Under such circumstance, in a lithography using aphoto-exposure that is used nowadays as a general technology, atechnology to achieve a finer and more precise pattern processing to alight source used is being developed.

Optical exposure has been widely used using g-line (436 nm) or i-line(365 nm) of a mercury-vapor lamp as a light source for lithography whena resist pattern is formed. It has been considered that a method ofusing an exposure light with a shorter wavelength is effective as ameans for achieving a further finer pattern. For this reason, KrFexcimer laser with a shorter wavelength of 248 nm has been used as anexposure light source instead of i-line (365 nm), for mass-productionprocess of a 64 M bit DRAM processing method. However, a light sourcewith far shorter wavelength is needed for manufacture of DRAM with apacking density of 1 G or more which needs a still finer processingtechnique (a processing dimension of 0.13 μm or less), and lithographyusing ArF excimer laser (193 nm) has been particularly examined.

In a monolayer resist method used for a typical resist patterningprocess, it is well known that a pattern fall due to a surface tensionof a developer occurs during the time of development if a ratio of apattern height to a pattern line width (aspect ratio) becomes larger.Accordingly, it has been known that, to form a pattern with a highaspect ratio on a non-planar substrate, a multilayer resist method inwhich patterning is done by laminating films having different dryetching properties has an advantage; and thus, a bilayer resistmethod—in which a resist layer formed of a silicon-containingphoto-sensitive polymer and an underlayer formed of an organic polymermainly comprised of elements of carbon, hydrogen, and oxygen, that isfor example, a novolak polymer are combined (Japanese Patent Laid-Open(kokai) No. H6-118651 and so on)—and a trilayer resist method—in which aresist layer formed of an organic photo-sensitive polymer used in amonolayer resist method, an intermediate layer formed of asilicon-containing polymer or of a silicon-containing CVD film, and anunderlayer formed of an organic polymer are combined—have been developed(Japanese Patent No. 4355943 and so on).

In the underlayer film of the foregoing multilayer resist methods,patterning is done by using the silicon-containing composition layerformed directly thereabove as a hard mask by dry etching with an oxygengas; and thus, an organic polymer mainly comprised of elements ofcarbon, hydrogen, and oxygen is used, and at the same time theunderlayer film is required to have an etching resistance during thetime of dry etching of a substrate to be processed, a film-formingproperty enabling to form a highly flat film on a substrate to beprocessed, and, depending on a use method, an antireflective functionduring the time of an exposure. For example, according to JapanesePatent No. 4355943, which discloses a technology relating to anunderlayer film composition for a bilayer or a trilayer resist method,by using an underlayer film such as those disclosed in the document, notonly an underlayer film pattern of a high precision can be formed butalso a high etching resistance to the etching condition of a substrateto be processed can be secured.

Here, FIG. 2 shows fluctuations of reflectivity of a substrate while kvalue (extinction coefficient) of an intermediate resist layer ischanged.

It follows from FIG. 2 that a sufficient antireflection effect to reducereflectivity of a substrate to 1% or less can be obtained by making anintermediate resist layer to have a low k value of 0.2 or less and aproper thickness.

In FIG. 3 and FIG. 4, change of reflectance is shown when filmthicknesses of the intermediate layer and the underlayer are changed inthe cases of k-values of the underlayer film being 0.2 and 0.6. Fromcomparison between FIG. 3 and FIG. 4, it can be seen that, in the casethat k-value of the resist underlayer film is higher (in the case of 0.6(FIG. 4)), reflectance can be reduced to 1% or lower by making the filmthickness thereof thinner. In the case that k-value of the resistunderlayer film is 0.2 (FIG. 3), in order to obtain reflectance of 1% infilm thickness of 250 nm, film thickness of the resist intermediate filmneeds to be thicker. If film thickness of the resist intermediate filmis increased, a load to the resist in the uppermost layer during thetime of dry etching in processing of the resist intermediate filmincreases; and thus, this is not desirable. In FIG. 3 and FIG. 4,reflection in the case of a dry exposure with NA of an exposureequipment lens being 0.85 is shown; it can be seen that, independent ofk-value in the underlayer film, reflectance of 1% or lower can beobtained by optimizing n-value (refractive index), k-value, and filmthickness of the intermediate layer in the trilayer process.

However, because of an immersion lithography, NA of a projection lens isover 1.0, and angle of an incident light not only to a resist but alsoto an antireflective film under the resist is becoming shallower. Anantireflective film suppresses the reflection not only by absorption dueto the film itself but also by a negating action due to an interventioneffect of a light. An intervention effect of a light is small in a slantlight, and thus, reflection thereof is increased.

Among the films in the trilayer process, it is the intermediate layerthat plays an antireflective role by using the intervention action of alight. The underlayer film is too thick for the intervention action sothat there is no antireflective effect by a negating effect due to theintervention effect. Reflection from surface of the underlayer filmneeds to be suppressed; to achieve this, the k-value needs to be madeless than 0.6 and the n-value near the value of the intermediate layerthereabove. If a transparency is too high due to a too small k-value,reflection from a substrate takes place; and thus, in the case of NA ofan immersion exposure being 1.3, the k-value is optimum in the rangebetween about 0.25 and about 0.48. Target n-values of both theintermediate layer and the underlayer are near the n-value of theresist, namely near 1.7.

As narrowing of a processed line width progresses, phenomena such aswiggling and bending of an underlayer film during etching of a substrateto be processed by using the underlayer film as a mask have beenreported (Proc. of Symp. Dry. Process, (2005) p 11). It is generallywell known that an amorphous carbon film formed by a CVD method(hereinafter CVD-C film) can very effectively prevent wiggling fromoccurring because amount of hydrogen atoms therein can be made extremelysmall.

However, in the case of a non-planar underlayment substrate to beprocessed, the difference in level needs to be made flat by anunderlayer film. By making the underlayer film flat, variance in filmthickness of an intermediate film and a photoresist formed thereabovecan be suppressed so that a focus margin in lithography can be enlarged.

In the CVD-C film using a raw material such as a methane gas, an ethanegas, and an acetylene gas, it is difficult to fill up the difference inlevel thereof to flat. On the other hand, in the case that theunderlayer film is formed by a spin coating method, there is a merit inthat concavity and convexity of the substrate can be filled up.

As mentioned above, the CVD-C film is poor in filling-up of thedifference in level, and in addition, introduction of a CVD equipment issometimes difficult due to its price and occupied footprint area. If awiggling problem could be solved by using an underlayer film compositioncapable of forming a film by a spin coating method, merits ofsimplification in process as well as in equipment thereof would belarge.

Accordingly, an underlayer film composition—having optimum n-value,k-value, and filling-up properties as an antireflective film, and havingexcellent antibending properties without wiggling during etching—and amethod for forming an underlayer film having such properties have beensought.

SUMMARY OF THE INVENTION

The present invention was made in view of the above circumstances, andhas an object to provide:

an underlayer film composition, especially for a trilayer resistprocess, that can form an underlayer film having reduced reflectance,namely, an underlayer film having optimum n-value and k-value, excellentfilling-up properties, high pattern-antibending properties, and notcausing line fall or wiggling after etching especially in a high aspectline that is thinner than 60 nm, anda patterning process using the same.

In order to solve the foregoing problems, the present invention providesa resist underlayer film composition, wherein the composition contains apolymer obtained by condensation of, at least,

one or more compounds represented by the following general formula (1-1)and/or (1-2), and

one or more kinds of compounds and/or equivalent bodies thereofrepresented by the following general formula (2):

wherein R¹ to R⁸ independently represent a hydrogen atom, a halogenatom, a hydroxyl group, an isocyanato group, a glycidyloxy group, acarboxyl group, an amino group, an alkoxyl group having 1 to 30 carbonatoms, an alkoxy carbonyl group having 1 to 30 carbon atoms, analkanoyloxy group having 1 to 30 carbon atoms, or anoptionally-substituted saturated or unsaturated organic group having 1to 30 carbon atoms, wherein two substituent groups arbitrarily selectedfrom each of R¹ to R⁴ or R⁵ to R⁸ may be bonded to form a cyclicsubstituent group within a molecule, and wherein X represents amonovalent organic group having 1 to 30 carbon atoms and containing oneor more of a 5-membered or a 6-membered aliphatic cyclic structure thatcontains a double bond.

As described above, a resist underlayer film—using a resist underlayerfilm composition containing a polymer obtained by condensation of, atleast, one or more compounds represented by the general formula (1-1)and/or (1-2), and one or more kinds of compounds and/or equivalentbodies thereof represented by the above general formula (2)—functions asan excellent antireflective film especially to an exposure light of ashort wavelength (i.e., the resist underlayer film is highlytransparent), and has not only optimum n-value and k-value but alsoexcellent filling-up properties and excellent pattern-antibendingproperties during the time of substrate processing.

The resist underlayer film composition can contain a polymer obtained bycondensation of

one or more compounds represented by the general formula (1-1) and/or(1-2),

one or more kinds of compounds and/or equivalent bodies thereofrepresented by the above general formula (2), and

one or more kinds of compounds and/or equivalent bodies thereofrepresented by the following general formula (3):Y—CHO  (3)

wherein Y is different from X and represents a hydrogen atom or anoptionally-substituted monovalent organic group having 1 to 30 carbonatoms.

If the resist underlayer film composition contains, as mentioned above,a polymer obtained by condensation of one or more compounds representedby the general formula (1-1) and/or (1-2), one or more kinds ofcompounds and/or equivalent bodies thereof represented by the generalformula (2), and one or more kinds of compounds and/or equivalent bodiesthereof represented by the general formula (3), the k-value and so oncan be controlled easily so that intended n-value and k-value can beobtained.

The polymer is preferably represented by the following general formula(4-1) or (4-2):

wherein R¹ to R⁸, X, and Y represent the same meanings as before, a, b,c, and d represent the ratio of each unit to the totality of repeatingunits with satisfying the relationships of 0≦d<c<a+b<1 and a+b+c+d=1,wherein * indicates a bonding position.

The resist underlayer film using the resist underlayer film compositioncontaining the polymer as mentioned above has a further excellentpattern-antibending property during the time of substrate processing.

The resist underlayer film composition can contain any one or more of acrosslinking agent, an acid generator, and an organic solvent.

If the resist underlayer film composition contains further, as mentionedabove, any one or more of an organic solvent, a crosslinking agent, andan acid generator, a crosslinking reaction in the resist underlayer filmcan be facilitated by baking and so on after application thereof onto asubstrate and so on. Accordingly, there is no fear of intermixingbetween a resist underlayer film like this and a resist upper layerfilm, thereby reducing diffusion of a low-molecular weight componentinto the resist upper layer film.

The present invention provides a patterning process on a body to beprocessed, wherein, at least, a resist underlayer film is formed on abody to be processed by using the resist underlayer film composition ofthe present invention, a resist intermediate film is formed on theresist underlayer film by using a resist intermediate film compositioncontaining a silicon atom, a resist upper layer film is formed on theresist intermediate film by using a resist upper layer film compositionof a photoresist composition, a circuit pattern is formed in the resistupper layer film, the resist intermediate film is etched by using theresist upper layer film formed with the pattern as a mask, the resistunderlayer film is etched by using the resist intermediate film formedwith the pattern as a mask, and further, the body to be processed isetched by using the resist underlayer film formed with the pattern as amask, whereby a pattern is formed on the body to be processed.

If patterning is done by a lithography using the resist underlayer filmcomposition of the present invention as mentioned above, a pattern of ahigh precision can be formed on a substrate.

The present invention provides a patterning process on a body to beprocessed, wherein, at least, a resist underlayer film is formed on abody to be processed by using the resist underlayer film composition ofthe present invention, a resist intermediate film is formed on theresist underlayer film by using a resist intermediate film compositioncontaining a silicon atom, an organic antireflective film (BARC) isformed on the resist intermediate film, a resist upper layer film isformed on the BARC by using a resist upper layer film composition of aphotoresist composition thereby forming a four-layer resist film, acircuit pattern is formed in the resist upper layer film, the BARC andthe resist intermediate film are etched by using the resist upperlayerfilm formed with the pattern as a mask, the resist underlayer film isetched by using the resist intermediate film formed with the pattern asa mask, and further, the body to be processed is etched by using theresist underlayer film formed with the pattern as a mask, whereby apattern is formed on the body to be processed.

As mentioned above, in the present invention, BARC can be formed betweenthe resist intermediate film and the resist upper layer film.

The present invention provides a patterning process on a body to beprocessed, wherein, at least, a resist underlayer film is formed on abody to be processed by using the resist underlayer film composition ofthe present invention, an intermediate film of an inorganic hard mask,selected from any of a silicon oxide film, a silicon nitride film, asilicon oxide nitride film, and an amorphous silicon film, is formed onthe resist underlayer film, a resist upper layer film is formed on theintermediate film of the inorganic hard mask by using a resist upperlayer film composition of a photoresist composition, a circuit patternis formed in the resist upper layer film, the intermediate film of theinorganic hard mask is etched by using the resist upperlayer film formedwith the pattern as a mask, the resist underlayer film is etched byusing the intermediate film of the inorganic hard mask formed with thepattern as a mask, and further, the body to be processed is etched byusing the resist underlayer film formed with the pattern as a mask,whereby a pattern is formed on the body to be processed.

As mentioned above, in the present invention, also in the case that anintermediate film of an inorganic hard mask is used, a pattern of a highprecision can be formed on a substrate when patterning is done by alithography using the resist underlayer film composition of the presentinvention.

The present invention provides a patterning process on a body to beprocessed, wherein, at least, a resist underlayer film is formed on abody to be processed by using the resist underlayer film composition ofthe present invention, an intermediate film of an inorganic hard mask,selected from any of a silicon oxide film, a silicon nitride film, asilicon oxide nitride film, and an amorphous silicon film, is formed onthe resist underlayer film, an organic antireflective film (BARC) isformed on the intermediate film of the inorganic hard mask, a resistupper layer film is formed on the BARC by using a resist upper layerfilm composition of a photoresist composition thereby forming afour-layer resist film, a circuit pattern is formed in the resist upperlayer film, the BARC and the intermediate film of the inorganic hardmask are etched by using the resist underlayer film formed with thepattern as a mask, the resist underlayer film is etched by using theintermediate film of the inorganic hard mask formed with the pattern asa mask, and further, the body to be processed is etched by using theresist underlayer film formed with the pattern as a mask, whereby apattern is formed on the body to be processed.

If BARC is formed on an intermediate film of a hard mask as mentionedabove, owing to two antireflective layers, reflection can be suppressedeven in an immersion exposure with a high NA beyond 1.0. In addition, inso doing, a footing profile of a photoresist pattern on the intermediatefilm of a hard mask can be reduced.

In this case, the intermediate film of an inorganic hard mask can beformed by a CVD method or an ALD method.

If the intermediate film of an inorganic hard mask is formed by a CVDmethod or an ALD method as mentioned above, an etching resistance can bemade high.

In addition, the patterning process of the resist upper layer film canbe any of a photolithography method with the wavelength range between 10nm or longer and 300 nm or shorter, a direct drawing method by anelectron beam, and a nanoimprinting method, or a combination of them.

As mentioned above, patterning can be done on the resist upper layerfilm by any of a photolithography method with a wavelength range between10 nm or more and 300 nm or less, a direct drawing method by an electronbeam, and a nanoimprinting method, or by a combination of them.

A developing method in the patterning process can be executed with analkaline development or a development by an organic solvent.

In so doing, an alkaline development or a development by an organicsolvent can be used in the present invention.

The body to be processed having, on a substrate of a semiconductordevice, a film of any of a metal film, a metal carbide film, a metaloxide film, a metal nitride film, and a metal oxide nitride film can beused.

In this case, the metal can be any of silicon, titanium, tungsten,hafnium, zirconium, chromium, germanium, aluminum, copper, and iron, oran alloy of these metals.

As mentioned above, in the present invention, the body to be processedthat is formed on a substrate of a semiconductor device with any of thefollowing films—a metal film, a metal carbide film, a metal oxide film,a metal nitride film, and a metal oxide nitride film—may be used,wherein the metal thereof includes, for example, any of silicon,titanium, tungsten, hafnium, zirconium, chromium, germanium, aluminum,copper, and iron, or an alloy of these metals.

As mentioned above, the resist underlayer film, formed by the resistunderlayer film composition of the present invention, functions as anexcellent antireflective film especially to the exposure to a light of ashort wavelength (i.e., the resist underlayer film is highlytransparent), and has not only optimum re-value and k-value but alsoexcellent filling-up properties and excellent pattern-antibendingproperties during the time of substrate processing. In addition, ifpatterning is done by a lithography using the resist underlayer filmcomposition of the present invention, a pattern of a high precision canbe formed on a substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view showing one embodiment of a patterningprocess (trilayer-resist process) according to the present invention.

FIG. 2 is a graph showing fluctuations of reflectivity of a substrate ina trilayer-resist process where the refractive index n value of a bottomresist layer is fixed at 1.5, the k value of the bottom resist layer isfixed at 0.6, the thickness of the bottom resist layer is fixed at 500nm, the refractive index n value of an intermediate resist layer isfixed at 1.5, the k value of the intermediate resist layer is changed inthe range of 0 to 0.4, and the thickness of the intermediate resistlayer is changed in the range of 0 to 400 nm.

FIG. 3 is a graph showing fluctuations of reflectivity of a substrate ina trilayer-resist process where the refractive index n value of a bottomresist layer is fixed at 1.5, the k value of the bottom resist layer isfixed at 0.2, the refractive index n value of an intermediate resistlayer is fixed at 1.5, the k value of the intermediate resist layer isfixed at 0.1, and the thicknesses of the bottom resist layer and theintermediate resist layer are changed respectively.

FIG. 4 is a graph showing fluctuations of reflectivity of a substrate ina trilayer-resist process where the refractive index n value of a bottomresist layer is fixed at 1.5, the k value of the bottom resist layer isfixed at 0.6, the refractive index n value of an intermediate resistlayer is fixed at 1.5, the k value of the intermediate resist layer isfixed at 0.1, and the thicknesses of the bottom resist layer and theintermediate resist layer are changed respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be explained.

As mentioned above, it is generally well known that a CVD-C film canreduce amount of hydrogen atoms contained therein to an extremely lowlevel so that it is very effective to prevent wiggling from occurring.However, there has been a problem that the CVD-C film formed by using araw material such as a methane gas, an ethane gas, and an acetylene gas,is poor in filling-up of a difference in level thereof to flat, and inaddition, introduction of a CVD equipment is sometimes difficult due toits price and occupied footprint area.

Accordingly, an underlayer film composition—having, as an antireflectivefilm, optimum n-value, k-value, and filling-up properties, and excellentantibending properties without wiggling during etching—and a method forforming an underlayer film using the said composition have been sought.

Inventors of the present invention had already found that aco-condensation body formed from dicyclopentadiene and a naphtholderivative shown below not only had optimum n-value and k-value inphoto-exposure to a light of a short wavelength such as 193 nm, but alsowas a material having an excellent etching resistance during etching ofa substrate (Japanese Patent No. 3981825).

(Wherein R¹ to R⁸ represent following meanings only in the aboveformula, regardless of other description in the present specification.Each R¹ to R⁸ independently represents a hydrogen atom, a hydroxylgroup, an optionally-substituted alkyl group having 1 to 6 carbon atoms,an optionally-substituted alkoxyl group having 1 to 6 carbon atoms, anoptionally-substituted alkoxy carboxyl group having 2 to 6 carbon atoms,an optionally-substituted aryl group having 6 to 10 carbon atoms, ahydroxyalkyl group having 1 to 6 carbon atoms, an isocyanate group, or aglycidyl group. m and n represent a positive integer.)

The reaction to form this naphthol co-condensation body is an appliedreaction shown below between a phenol and dicyclopentadiene to anaphthol system (here, * in the below reaction scheme indicates abonding position).

A conventional film-curing reaction during formation of a resistunderlayer film has been generally based on a reaction mechanism forcuring by crosslinking among polymers via a crosslinking agent(indicated by • in the following scheme).

In order to further improve an antibending property while maintainingoptimum n-value and k-value in exposure to a light of a short wavelengthsuch as 193 nm, inventors of the present invention introduced a doublebond capable of progressing a reaction according to the above reactionmechanism; and as a result, inventors of the present invention foundthat, as shown in a below equation, not only crosslinking among polymersby intervention of a crosslinking agent, but also direct crosslinkingamong polymers themselves without intervention of a crosslinking agentcould be progressed thereby improving a crosslinking density of a filmafter baking and thus suppressing pattern deformation after etching,thereby completing the present invention.

(Wherein the figure shown by

represents a five- or a six-membered aliphatic ring structure having adouble bond.)

Hereinafter, embodiments of the present invention will be explained, butthe present invention is not limited by them.

The present invention is related to a resist underlayer filmcomposition, wherein the composition contains a polymer obtained bycondensation of, at least, one or more compounds represented by thefollowing general formula (1-1) and/or (1-2), and one or more kinds ofcompounds and/or equivalent bodies thereof represented by the followinggeneral formula (2) (hereinafter, sometimes referred to as “aldehydecompound (2)”).

(Wherein (1-1) and (1-2), R¹ to R⁸ independently represent a hydrogenatom, a halogen atom, a hydroxyl group, an isocyanato group, aglycidyloxy group, a carboxyl group, an amino group, an alkoxyl grouphaving 1 to 30 carbon atoms, an alkoxy carbonyl group having 1 to 30carbon atoms, an alkanoyloxy group having 1 to 30 carbon atoms, or anoptionally-substituted saturated or unsaturated organic group having 1to 30 carbon atoms. In addition, two substituent groups arbitrarilyselected from each of R¹ to R⁴ or R⁵ to R⁸ may be bonded to form acyclic substituent group within a molecule. Wherein X represents amonovalent organic group having 1 to 30 carbon atoms and containing oneor more of a 5-membered or a 6-membered aliphatic cyclic structure thatcontains a double bond.)

Herein, the term “organic group” means a group, which includes carbon,and which may additionally include hydrogen, as well as nitrogen,oxygen, sulfur, or the like (hereinafter represents the same meaning).

When a resist underlayer film composition containing a polymer like thisis used, a film-curing reaction based on the above reaction mechanismcan progress during formation of a resist underlayer film; and thus, notonly crosslinking among polymers by intervention of a crosslinking agentbut also direct crosslinking among polymers themselves withoutintervention of a crosslinking agent can progress, so that acrosslinking density of a film after baking can be improved and patterndeformation after etching can be suppressed. In addition, optimumn-value and k-value can be obtained in photo-exposure to a light of ashort wavelength such as 193 nm. Further in addition, an excellentfilling-up property can be obtained.

Herein, examples of the naphthalene (derivative) represented by thegeneral formula (1-1) (hereinafter sometimes referred to as “naphthalenederivative (1-1)”) include naphthalene, 1-methylnaphthalene,2-methylnaphthalene, 1,3-dimethylnaphthalene, 1,5-dimethylnaphthalene,1,7-dimethylnaphthalene, 2,7-dimethylnaphthalene, 2-vinylnaphthalene,2,6-divinylnaphthalene, acenaphthene, acenaphthylene, anthracene,1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dimethoxynaphthalene,2,7-dimethoxynaphthalene, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol,4-methoxy-1-naphthol, 7-methoxy-2-naphthol, 1,2-dihydroxynaphthalene,1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene,1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,1,8-dihydroxynaphthalene, 5-amino-1-naphthol,2-methoxycarbonyl-1-naphthol, 1-(4-hydroxyphenyl) naphthalene,6-(4-hydroxyphenyl)-2-naphthol, 6-(cyclohexyl)-2-naphthol,1,1′-bi-2,2′-naphthol, 6,6′-bi-2,2′-naphthol,9,9-bis(6-hydroxy-2-naphthyl)fluorene, 6-hydroxy-2-vinylnaphthalene,1-hydroxymethylnaphthalene, 2-hydroxymethylnaphthalene, and the like.

Examples of the benzene (derivative) represented by the general formula(1-2) (hereinafter sometimes referred to as “benzene derivative (1-2)”)include toluene, o-xylene, m-xylene, p-xylene, cumene, indane, indene,mesitylene, biphenyl, fluorene, phenol, anisole, o-cresol, m-cresol,p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol,3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol,2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-t-butylphenol,3-t-butylphenol, 4-t-butylphenol, resorcinol, 2-methylresorcinol,4-methylresorcinol, 5-methylresorcinol, catechol, 4-t-butylcatechol,2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol,4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol,2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, 4-phenylphenol,tritylphenol, pyrogallol, thymol, phenylglycidylether 4-fluorophenol,3,4-difluorophenol, 4-trifluoromethlyphenol, 4-clorophenol,9,9-bis(4-hydroxyphenyl)fluorene, styrene, 4-t-butoxystyrene,4-acetoxystyrene, 4-methoxystyrene, divinylbenzene, benzylalcohol, andthe like.

Each of the compounds represented by the general formulae (1-1) and(1-2) may be used singly, or in a combination of two or more kindsthereof in order to control n-value, k-value, and an etching resistance.

Examples of aldehyde compound represented by the general formula (2)containing one or more of a 5-membered or a 6-membered aliphatic cyclicstructure that contains a double bond include the following formulae.

Further, an equivalent body of the aldehyde compound shown here may alsobe used. Examples of the equivalent body of the general formula (2)include a compound having the following general formulae.

(X is defined similarly to the foregoing X, and each R′ represents anidentical or a different monovalent hydrocarbon group having 1 to 10carbon atoms.)

(X is defined similarly to the foregoing X, and R″ represents a divalenthydrocarbon group having 1 to 10 carbon atoms.)<In the Case that a Hydrogen Atom is Bonded to the α-Carbon Atom of theFormyl Group.>

(X′ represents an organic group having one less hydrogen atom from theforegoing X, and R′ represents a monovalent hydrocarbon group having 1to 10 carbon atoms.)

Specific examples of the equivalent body of (2A) are represented by thefollowing formulae, and similarly to the case of other aldehydecompounds, an equivalent body can be used.

Specific examples of the equivalent body of (2B) are represented by thefollowing formulae, and similarly to the case of other aldehydecompounds, an equivalent body can be used.

Specific examples of the equivalent body of (20) are represented by thefollowing formulae, and similarly to the case of other aldehydecompounds, an equivalent body can be used.

Ratio of an aldehyde compound (2) to a naphthalene derivative (1-1) anda benzene derivative (1-2) is preferably 0.01 to 5 moles, or morepreferably 0.1 to 2 moles, relative to 1 mole of the totality of (1-1)and (1-2).

The resist underlayer film composition of the present invention maycontain a polymer obtained by condensation of

one or more compounds represented by the general formula (1-1) and/or(1-2),

one or more kinds of compounds and/or equivalent bodies thereofrepresented by the general formula (2), and

one or more kinds of compounds and/or equivalent bodies thereofrepresented by the following general formula (3) (hereinafter sometimesreferred to as “aldehyde compound (3)”).Y—CHO  (3)

(Wherein Y is different from X and represents a hydrogen atom or anoptionally-substituted monovalent organic group having 1 to 30 carbonatoms.)

Examples of the aldehyde compound represented by the general formula (3)include formaldehyde, trioxane, paraformaldehyde, acetaldehyde,propylaldehyde, adamantanecarboaldehyde, benzaldehyde,phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde,o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde,o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde,o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde,p-ethylbenzaldehyde, p-n-butylbenzaldehyde, 1-naphthylaldehyde,2-naphthylaldehyde, anthracenecarboaldehyde, pyrenecarboaldehyde,furfural, methylal, and the like.

In addition, similarly to the case of an aldehyde compound representedby the general formula (2), an aldehyde equivalent body can be used.Specific examples of the equivalent body of the general formula (3)include a compound having the following general formulae.

(Y is defined similarly to the foregoing Y, and each R′ represents anidentical or a different monovalent hydrocarbon group having 1 to 10carbon atoms.)

(Y is defined similarly to the foregoing Y, and R″ represents a divalenthydrocarbon group having 1 to 10 carbon atoms.)<In the Case that a Hydrogen Atom is Bonded to the α-Carbon Atom of theFormyl Group.>

(Y′ represents an organic group having one less hydrogen atom from theforegoing Y, and R′ represents a monovalent hydrocarbon group having 1to 10 carbon atoms.)

Examples of the polymer as described above, which is contained in theresist underlayer film composition of the present invention, include acompound having the following general formula (4-1) or (4-2).

(Wherein R¹ to R⁸, X, and Y represent the same meanings as before, anda, b, c, and d represent the ratio of each unit to the totality ofrepeating units with satisfying the relationships of 0≦d<c<a+b<1 anda+b+c+d=1. Here, * indicates a bonding position.)

Ratio of an aldehyde compound (2) and an aldehyde compound (3) to anaphthalene derivative (1-1) and a benzene derivative (1-2) ispreferably 0.01 to 5 moles, and (3)<(2), or more preferably 0.05 to 2moles, relative to 1 mole of the totality of (1-1) and (1-2).

Ratio to the totality of repeating units is preferably 0.1<a+b<1, ormore preferably 0.3<a+b<0.95.

Polymers represented by the general formulae (4-1) and (4-2)(hereinafter sometimes referred to as “polymer (4-1)” and “polymer(4-2)”) can be produced by a condensation reaction (for example, acondensation by dehydration) of the corresponding compounds, usually byusing an acid or a base as a catalyst in a solvent or without solvent atroom temperature or with cooling or heating as appropriate.

Examples of the solvent to be used include alcohols such as methanol,ethanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol,diethylene glycol, glycerol, methyl cellosolve, ethyl cellosolve, butylcellosolve, and propylene glycol monomethyl ether; ethers such asdiethyl ether, dibutyl ether, diethylene glycol diethyl ether,diethylene glycol dimethyl ether, tetrahydrofurane, and 1,4-dioxane;chlorinated solvents such as methylene chloride, chloroform,dichloroethane, and trichloroethylene; hydrocarbons such as hexane,heptane, benzene, toluene, xylene, and cumene; nitriles such asacetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutylmethyl ketone; esters such as ethyl acetate, n-butyl acetate, andpropylene glycol methyl ether acetate; lactones such as γ-butyrolactone;and non-protic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and hexamethyl phosphoric triamide. These may be used singlyor as a mixture of two or more of them. These solvents may be used inthe range between 0 and 2000 parts by mass relative to 100 parts by massof raw materials of the reaction.

Examples of the acid catalyst to be used include inorganic acids such ashydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid, and heteropolyacid; organic acids such as oxalic acid,trifluoroacetic acid, methane sulfonic acid, benzene sulfonic acid,p-toluene sulfonic acid, and trifluoromethane sulfonic acid; and Lewisacids such as aluminum trichloride, aluminum ethoxide, aluminumisopropoxide, boron trifluoride, boron trichloride, boron tribromide,tin tetrachloride, tin tetrabromide, dibutyltin dichloride, dibutyltindimethoxide, dibutyltin oxide, titanium tetrachloride, titaniumtetrabromide, titanium (IV) methoxide, titanium (IV) ethoxide, titanium(IV) isopropoxide, and titanium (IV) oxide. Examples of the basecatalyst to be used include an inorganic base such as sodium hydroxide,potassium hydroxide, barium hydroxide, sodium carbonate, sodiumbicarbonate, potassium carbonate, lithium hydride, sodium hydride,potassium hydride, and calcium hydride; an alkyl metal such as methyllithium, n-butyl lithium, methyl magnesium chloride, and ethyl magnesiumbromide; an alkoxide such as sodium methoxide, sodium ethoxide, andpotassium t-butoxide; and an organic base such as triethyl amine,diisopropyl ethyl amine, N,N-dimethylaniline, pyridine, and4-dimethylamino pyridine. The amount thereof relative to raw materialsis 0.001 to 100% by mass, or preferably 0.005 to 50% by mass.Temperature of the reaction is preferably between −50° C. and aboutboiling point of a solvent, or more preferably between room temperatureto 100° C.

As a method for carrying out the condensation reaction, there are amethod in which a naphthalene derivative (1-1), a benzene derivative(1-2), aldehyde compounds (2) and (3), and a catalyst are charged all atonce and a method in which a naphthalene derivative (1-1), a benzenederivative (1-2), and aldehyde compounds (2) and (3) are gradually addedin the presence of a catalyst.

After the condensation reaction, in order to remove a unreacted rawmaterial, catalyst, and so on that are present in the reaction system, amethod in which temperature of the reaction vessel is increased to 130to 230° C. at about 1 to about 50 mmHg to remove volatile components, amethod in which a polymer is fractionated by adding an appropriatesolvent or water, a method in which a polymer is dissolved into a goodsolvent then reprecipitated into a poor solvent, and so on, can be usedby selecting them depending on properties of reaction products obtained.

Polystyrene-equivalent molecular weight of a polymer represented by thegeneral formula (4-1) or (4-2) thus obtained is preferably 500 to100,000, or in particular 1,000 to 20,000, as the weight-averagemolecular weight (Mw). The molecular-weight distribution is preferably1.2 to 8, while a narrow molecular weight distribution, obtained bycutting a monomer component, an oligomer component, or a low-molecularweight body of a molecular weight (Mw) of 1,000 or less, can bring abouta higher crosslinking efficiency and prevent pollution around a bakingcup from occurring due to suppression of a volatile component duringbaking.

In addition, into the compound represented by the general formula (4-1)or (4-2) may be introduced a condensed aromatic or an alicyclicsubstituent.

Specific examples of the introducible substituent group include thefollowing.

Among them, for an exposure to the light of 248 nm, a polycyclicaromatic group, such as an anthracenemethyl group and a pyrenemethylgroup, is most preferably used. To increase transparency at 193 nm, agroup having an alicyclic structure or a naphthalene structure ispreferably used. On the other hand, a benzene ring has a window toincrease transparency at 157 nm, and thus, absorbance needs to beincreased by shifting an absorption wavelength. A furane ring has anabsorption at a shorter wavelength than a benzene ring with theabsorption at 157 nm being somewhat increased, though its effect issmall. A naphthalene ring, an anthracene ring, and a pyrene ringincrease the absorption due to shifting of the absorption wavelengthtoward a longer wavelength, and these aromatic rings have an effect toincrease an etching resistance; and thus, they are preferably used.

A substituent group may be introduced by a method in which an alcoholhaving bonding site of a hydroxyl group in the substituent group isintroduced into a polymer at an ortho-position or a para-positionrelative to a hydroxyl group or an alkyl group thereof in the presenceof an acid catalyst in accordance with a reaction mechanism of anaromatic electrophilic substitution. Examples of the acid catalystinclude hydrochloric acid, nitric acid, sulfuric acid, formic acid,oxalic acid, acetic acid, methane sulfonic acid, n-butane sulfonic acid,camphor sulfonic acid, tosyl acid, and trifluoromethane sulfonic acid.Amount of the acid catalyst is 0.001 to 20 parts by mass, relative to100 parts by mass of a polymer before the reaction. Amount of theintroduced substituent group is in the range between 0 and 0.8 molerelative to 1 mole of a monomer unit in the polymer.

In addition, blending with another polymer may be allowed. Examples ofthe blending polymer include a polymer, obtained from a compoundrepresented by the general formula (1-1) or (1-2) as the raw materialwhile having a different composition, and a heretofore known novolakresin. Blending a polymer like this affords a role to improve coatingproperties by a spin coating method and filling-up properties of anon-planar substrate. In addition, a material having a higher carbondensity and a higher etching resistance can be chosen.

Examples of the heretofore known novolak resin usable for blendinginclude condensation-dehydration compounds obtained by condensation offormaldehyde and phenol, o-cresol, m-cresol, p-cresol,2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol,3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol,2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-t-butylphenol,3-t-butylphenol, 4-t-butylphenol, 2-phenylphenol, 3-phenylphenol,4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol,4-naphthylphenol, 4-tritylphenol, resorcinol, 2-methylresorcinol,4-methylresorcinol, 5-methylresorcinol, catechol, 4-t-butylcatechol,2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol,4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol,2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, pyrogallol, thymol,isothymol, 4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′-dimethyl-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′-diallyl-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′-difluoro-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′-diphenyl-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,2′-dimethoxy-4,4′-(9H-fluorene-9-ylidene)bisphenol,2,3,2′3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,3,3,3′,3′-tetramethyl-2,3,2′3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,3,3,3′,3′,4,4′-hexamethyl-2,3,2′3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,2,3,2′3′-tetrahydro-(1,1′)-spirobiindene-5,5′-diol,5,5′-dimethyl-3,3,3′,3′-tetramethyl-2,3,2′3′-tetrahydro-(1,1′)-spirobiindene-6,6′-diol,1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol,7-methoxy-2-naphthol, dihydroxynaphthalene such as1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and2,6-dihydroxynaphthalene, 3-hydroxy-naphthalene-2-methyl carboxylicacid, hydroxyindene, hydroxyanthracene, bisphenol, or trisphenol;polystyrene; polyvinylnaphthalene; polyvinylanthracene;polyvinylcarbazole; polyindene; polyacenaphthylene; polynorbornene;polycyclodecene; polytetracyclododecene; polynortricyclene;poly(meth)acrylate; and copolymer thereof.

Moreover, other heretofore known resins such as nortricyclene copolymer,hydrogenated-naphtholnovolak resin, naphtholdicyclopentadiene copolymer,phenoldicyclopentadiene copolymer, fluorenebilphenolnovolak resin,acenaphthylene copolymer, indene copolymer, fullerene having a phenolgroup, bisphenol compound and novolak resin thereof, dibisphenolcompound and novolak resin thereof, novolak resin of adamantane phenolcompound, hydroxyvinylnaphthalene copolymer, bisnaphthol compound andnovolak resin thereof, ROMP, resin compounds such as tricyclopentadienecopolymer, and resin compounds of fullerenes can be blended.

Amount of the blending compound or amount of the blending polymer is 0to 1,000 parts by mass, or preferably 0 to 500 parts by mass, relativeto 100 parts by mass of a compound represented by the general formula(4-1) or (4-2).

The resist underlayer film composition of the present invention maycontain a crosslinking agent with a purpose to facilitate a crosslinkingreaction inside the resist underlayer film by baking and so on afterapplication thereof to a substrate and so on, so that a chance ofintermixing of the resist underlayer film with the resist upper layerfilm may be reduced thereby reducing diffusion of a low-molecular weightcomponent to the resist upper layer film.

A crosslinking agent usable in the present invention including thosematerials described in paragraphs (0055) to (0060) of Japanese PatentLaid-Open Application No. 2007-199653 may be added.

In the present invention, an acid generator to further facilitate athermal crosslinking reaction may be added. An acid generator generatesan acid by thermal decomposition or by light irradiation; and any ofthem may be added. Specifically, those materials described in paragraphs(0061) to (0085) of Japanese Patent Laid-Open Application No.2007-199653 may be added.

In addition, a basic compound to improve storage stability may be addedinto the resist underlayer film composition used in patterning processof the present invention, as will be described later. The basic compoundplays a role of the quencher to an acid that is generated faintly froman acid generator, whereby a crosslinking reaction by the acid generatedtherefrom may be prevented from progressing.

Basic compounds specifically described in paragraphs (0086) to (0090) ofJapanese Patent Laid-Open Application No. 2007-199653 may be added.

In addition, in preparation of the resist underlayer film composition ofthe present invention, an organic solvent may be used.

The organic solvent usable in the resist underlayer film composition forpatterning process of the present invention is not particularly limited,provided that the organic solvent can dissolve the base polymer, theacid generator, the crosslinking agent, and other additives, asdescribed before. Specifically, those solvents described in paragraphs(0091) to (0092) of Japanese Patent Laid-Open Application No.2007-199653 may be added.

Still in addition, in the underlayer film-forming composition used inpatterning process of the present invention, a surfactant may be addedto improve applicability in spin coating. Surfactants described inparagraphs (0165) to (0166) of Japanese Patent Laid-Open Application No.2008-111103 may be used.

Specific example of the patterning process of the present inventionusing the resist underlayer film composition prepared as mentioned aboveincludes the following.

The present invention provides a patterning process on a body to beprocessed, wherein, at least, a resist underlayer film is formed on abody to be processed by using the resist underlayer film composition ofthe present invention, a resist intermediate film is formed on theresist underlayer film by using a resist intermediate film compositioncontaining a silicon atom, a resist upper layer film is formed on theresist intermediate film by using a resist upper layer film compositionof a photoresist composition, a circuit pattern is formed in the resistupper layer film, the resist intermediate film is etched by using theresist upper layer film formed with the pattern as a mask, the resistunderlayer film is etched by using the resist intermediate film formedwith the pattern as a mask, and further, the body to be processed isetched by using the resist underlayer film formed with the pattern as amask, whereby a pattern is formed on the body to be processed.

In this case, as to the resist intermediate film, an intermediate filmof an inorganic hard mask, selected from any of a silicon oxide film, asilicon nitride film, a silicon oxide nitride film (SiON film), and anamorphous silicon film, may be formed.

In the case that the intermediate film of an inorganic hard mask isformed on the resist underlayer film, a silicon oxide film, a siliconnitride film, a silicon oxide nitride film (SiON film), or an amorphoussilicon film is formed by a CVD method, an ALD method, and the like. Amethod for forming a silicon nitride film is described in JapanesePatent Laid-Open Publication No. 2002-334869, International PatentLaid-Open Publication No. 2004/066377, and so on. Thickness of theinorganic hard mask is 5 to 200 nm, or preferably 10 to 100 nm; amongthe foregoing films, a SiON film, which is highly effective as anantireflective film, is most preferably used. Because temperature of asubstrate during the time of forming a SiON film is 300 to 500° C., theunderlayer film needs to be endurable the temperature of 300 to 500° C.The resist underlayer film composition of the present invention has ahigh heat resistance so that it is endurable the high temperature of 300to 500° C.; and thus, a combination of the inorganic hard mask formed bya CVD method or an ALD method with the resist underlayer film formed bya spin coating method may be possible.

A photoresist film may be formed as the resist upper layer film on theresist intermediate film or the intermediate film of an inorganic hardmask as mentioned above; but also an organic antireflective film (BARC)may be formed on the resist intermediate film or on the intermediatefilm of an inorganic hard mask by spin coating, followed by formation ofa photoresist film thereonto.

Especially in the case that the intermediate film of an inorganic hardmask such as a SiON film is used, reflection can be suppressed even inan immersion exposure with a high NA of beyond 1.0 by virtue of a bilayer of the SiON film and BARC. Another merit of forming BARC residesin that a footing profile of the photoresist pattern immediately abovethe SiON film can be suppressed.

In a process of forming the resist underlayer film in the patterningprocess of the present invention, similarly to the photoresist, theforegoing resist underlayer film composition is applied onto a body tobe processed by a spin coating method and the like. By using a spincoating method and the like, an excellent filling-up property can beobtained. After spin coating, a solvent is evaporated, and then bakingis carried out to prevent mixing with the resist upper layer film andthe resist intermediate film from occurring and to facilitate acrosslinking reaction. The baking is carried out in the temperaturerange between above 100° C. and 600° C. or lower and with the time inthe range between 10 and 600 seconds, or preferably in the range between10 and 300 seconds. The baking temperature is preferably between 150° C.or higher and 500° C. or lower, or more preferably between 180° C. orhigher and 400° C. or lower. In view of effects on device damage andwafer deformation, upper limit of the heatable temperature in alithography wafer process is 600° C. or lower, or preferably 500° C. orlower.

Atmosphere during the time of baking may be air; but it is preferablethat an inert gas such as N₂, Ar, and He be charged to reduce oxygen sothat oxidation of the resist underlayer film may be prevented fromoccurring. To prevent oxidation of the underlayer film from occurring,oxygen concentration needs to be controlled, preferably at 1,000 ppm orlower, or more preferably 100 ppm or lower. Prevention of oxidation ofthe resist underlayer film during baking from occurring is desirablebecause increase in absorption and decrease in etching resistance can beavoided.

Meanwhile, thickness of the resist underlayer film can be arbitrarilyselected, though the range thereof is preferably 30 to 20,000 nm, or inparticular 50 to 15,000. In the case of the trilayer process, afterforming the resist underlayer film, a resist intermediate filmcontaining a silicon atom may be formed thereunto, followed by formationof a resist upper, layer film not containing a silicon atom (monolayerresist film).

As to the resist intermediate film containing a silicon atom in thetrilayer process as mentioned above, an intermediate film based onpolysiloxane is used preferably. When this resist intermediate filmcontaining a silicon atom is made to have an effect of an antireflectivefilm, reflection can be suppressed. Specifically, a material includingpolysiloxanes, described in Japanese Patent Laid-Open Publication No.2004-310019, Japanese Patent Laid-Open Publication No. 2009-126940 andso on, can be mentioned.

When a resist underlayer film using a material containing many aromaticgroups and having a high etching resistance to a substrate is used,especially for exposure to the light of 193 nm wavelength, the k-valueand the substrate reflectance become high; but the substrate reflectancecan be reduced to 0.5% or less by suppressing reflection by the resistintermediate film.

The intermediate film of an inorganic hard mask as mentioned above canbe formed by a CVD method or an ALD method.

The resist upper layer film in the trilayer resist film may be any of apositive-type and a negative-type, wherein the same composition as agenerally used photoresist composition may be used. In the case that theresist upper layer film is formed by the foregoing photoresistcomposition, a spin coating method is preferably used, similarly to thecase of forming the resist underlayer film. After spin coating of thephotoresist composition, prebaking is carried out, preferably in thetemperature range between 60 and 180° C. for time between 10 and 300seconds. Thereafter, exposure, post-exposure bake (PEB), and developmentare carried out according to respective conventional methods to obtain aresist pattern. Meanwhile, thickness of the resist upper layer film isnot particularly limited, though the thickness between 30 and 500 nm, inparticular between 50 and 400 nm, is preferable.

As to the foregoing patterning process of the resist upper layer film,patterning may be done by a method such as a photolithography methodwith the wavelength range between 10 nm or longer and 300 nm orshorter—specifically excimer laser beams of 248 nm, 193 nm, and 157 nm,and a soft X-ray of 20 nm or shorter—, a direct drawing method by anelectron beam, and a nanoimprinting method, or a combination of them.

Specific examples of the development method in the patterning process asmentioned above include an alkaline development and a development by anorganic solvent.

Then, etching is carried out by using the obtained resist pattern as amask. Etching of the resist intermediate film in the trilayer process,especially etching of the inorganic hard mask is carried out by using aCF gas and a resist pattern as a mask. Then, etching of the resistunderlayer film is carried out by using an oxygen gas or a hydrogen gasand a resist intermediate film pattern, especially an inorganic hardmask pattern, as a mask.

Subsequent etching of the body to be processed may be carried out alsoby a conventional method; for example, etching is carried out by using agas mainly comprised of a CF gas in the case of the substrate beingSiO₂, SiN, or a silica-type low-dielectric insulating film, while, inthe case of p-Si, Al, or W, etching is carried out by a gas mainlycomprised of a chlorine-type gas and a bromine-type gas. In the casethat processing of the substrate is carried out by etching with a CFgas, the intermediate layer containing a silicon atom in the trilayerprocess is removed at the same time as processing of the substrate. Inthe case that etching of the substrate is carried out by a chlorine-typegas or a bromine-type gas, removal of the intermediate layer containinga silicon atom needs to be carried out separately by dry etching with aCF gas after processing of the substrate.

The resist underlayer film formed by the pattering process of thepresent invention for forming the resist underlayer film has acharacteristic of excellent etching resistance to these bodies to beprocessed.

Meanwhile, as to the body to be processed, the one such as those having,on a substrate of a semiconductor device (substrate), any of thefollowing metal films (hereinafter, “layer to be processed”)—a metalfilm, a metal carbide film, a metal oxide film, a metal nitride film,and a metal oxide nitride film—may be used.

The substrate is not limited and may be Si, an amorphous silicon (α-Si),p-Si, SiO₂, SiN, SiON, W, TiN, Al, or the like. The substrate may be amaterial different from the layer to be processed may be used.

The layer to be processed may be made of Si, SiO₂, SiON, SiN, p-Si,α-Si, W, W—Si, Al, Cu, Al—Si, or the like; various low dielectricconstant films, or etching stopper films. Typically, the layer may beformed at a thickness of 50 to 10,000 nm, in particular at a thicknessof 100 to 5,000 nm.

One embodiment of the patterning process of the present invention(trilayer process) will be specifically shown as following withreferring to FIG. 1.

In the case of the trilayer process, as shown in FIG. 1 (A), after theresist underlayer film 3 is formed by the present invention on the filmto be processed 2 that is laminated on the substrate 1, the resistintermediate film 4 is formed, and then, the resist upper layer film 5is formed thereonto.

Then, as shown in FIG. 1 (B), the intended part 6 of the resist upperlayer film is exposed, which is then followed by PEB and development toform the resist pattern 5a (FIG. 1 (C)). By using the resist pattern 5athus obtained as a mask, the resist intermediate film 4 is processed byetching with a CF gas to form the resist intermediate film pattern 4a(FIG. 1 (D)). After removal of the resist pattern 5a, by using theresist intermediate film pattern 4a thus obtained as a mask, the resistunderlayer film 3 is etched by an oxygen plasma method to form theresist underlayer film pattern 3a (FIG. 1 (E)). Further, after removalof the resist intermediate film pattern 4a, the film to be processed 2is processed by etching using the resist underlayer film pattern 3a as amask to form the pattern 2a on the substrate (FIG. 1 (F)).

Meanwhile, in the case that the intermediate film of an inorganic hardmask is used, the resist intermediate film 4 shows the intermediate filmof an inorganic hard mask, and the resist intermediate film pattern 4ais the intermediate film pattern of an inorganic hard mask 4a.

In the case that BARC is formed, BARC is formed between the resistintermediate film (or intermediate film of an inorganic hard mask) 4 andthe resist upper layer film 5. Etching of BARC may be carried outcontinuously in advance of etching of the resist intermediate film (orintermediate film of an inorganic hard mask) 4, or etching of the resistintermediate film (or intermediate film of an inorganic hard mask) 4 maybe carried out by changing an equipment and the like after only BARC isetched.

EXAMPLES

Hereafter the present invention will be explained in detail withreference to Synthesis Examples, Comparative Synthesis Examples,Examples and Comparative Examples. However, the present invention is notlimited thereto.

In addition, as for measurement of molecular weight, mass averagemolecular weight (Mw) and number average molecular weight (Mn) relativeto polystyrene standards were determined by gel permeationchromatography (GPC), and molecular-weight distribution (Mw/Mn) wasdetermined.

Synthesis Example 1

Into a 500-mL flask was taken 72 g of 1-naphthol (0.5 mole), 40 g ofnorbornene carboaldehyde (0.33 mole), and 200 g of methyl cellosolve;and then, into the resulting mixture was added 20 g of a methylcellosolve solution of 20% p-toluenesulfonic acid with stirring at 65°C. After stirring was continued at the same temperature for 2 hours, thecontent therein was cooled to room temperature, transferred to aseparation funnel containing 800 mL of ethyl acetate, and washed with500 mL of deionized water; and then washing water was discarded. Thiswashing and separation procedures were repeated, whereby the reactioncatalyst and metal impurities were removed. After the obtained solutionwas concentrated under reduced pressure, 500 mL of THF was added to theresidue, and then a polymer was reprecipitated by 4,000 mL of hexane.The precipitated polymer was collected by filtration and then driedunder reduced pressure to obtain Polymer 1.

The weight-average molecular weight (Mw) (relative to polystyrenestandard) and the molecular-weight distribution (Mw/Mn) of Polymer 1were obtained by gel permeation chromatography (GPC). In addition, amole ratio of naphthol (a) and norbornene (b) in Polymer 1 was obtainedby ¹H-NMR. The results are shown below.

Mole ratio a:b=0.60:0.40

Weight-average molecular weight (Mw)=4,300

Molecular-weight distribution (Mw/Mn)=6.50

Synthesis Examples 2 to 12

Polymers 2 to 12 shown in Table 2 were obtained by using the materialsshown in Table 1 under the same condition as Synthesis Example 1.

TABLE 1 Synthesis Compond (1-1) Reaction Reaction Example and/or (1-2)solvent catalyst Compound (2) Compound (3)  1

methyl cellosolve 200 g A 20 g

 2

methyl cellosolve 200 g A 20 g

 3

methyl cellosolve 200 g A 20 g

paraformaldehyde 5 g  4

methyl cellosolve 200 g A 20 g

 5

methoxypropanol 200 g B 20 g

 6

methyl cellosolve 200 g A 20 g

 7

methoxypropanol 200 g B 20 g

 8

methoxypropanol 200 g B 20 g

 9

 

methoxypropanol 200 g B 20 g

(Comparative Synthesis Example) 10

methyl cellosolve 200 g A 20 g

11

methyl cellosolve 200 g A 20 g

12

methyl cellosolve 200 g A 20 g

Reaction catalyst A: a methyl cellosolve solution of 20%p-toluenesulfonic acid Reaction catalyst B: a methoxy propanol solutionof 20% p-toluenesulfonic acid

TABLE 2 Weight-average Molecular-weight Product molecular distributionSynthesis Example (mole ratio) weight (Mw) (Mw/Mn)  1 Polymer 1

4300 6.50  2 Polymer 2

4500 6.97  3 Polymer 3

3500 6.29  4 Polymer 4

3600 6.04  5 Polymer 5

4700 5.31  6 Polymer 6

3900 5.87  7 Polymer 7

4100 6.95  8 Polymer 8

3800 6.17  9 Polymer 9

4200 6.30 Comparative Synthesis Example 10 Polymer 10

4100 6.36 11 Polymer 11

3400 5.88 12 Polymer 12

3700 6.20

Examples and Comparative Examples

Each solution for forming a resist underlayer film (SOL-1 to SOL-12) wasprepared by dissolving 20 parts by mass of any of the polymer 1 to 12obtained in the above Synthesis Examples, 1 part by mass of an acidgenerator shown by the following AG1, and 4 parts by mass of acrosslinking agent shown by the following CR1, in 100 parts by mass of apropylene glycol monomethyl ether acetate solution containing 0.1% bymass of FC-430 (produces by Sumitomo 3M Ltd.), and filtrating thesolution through a 0.1 μm filter made from the fluorine resin.

This solution was applied (by spin coating) onto a silicon substrate,and then baked at 250° C. for 60 seconds to obtain each of coated filmsUDL-1 to UDL-12 having film thickness of 200 nm. Refractive indexes (nand k) of these films at the wavelength of 193 nm were measured with aspectroscopic ellipsometer with a variable incident light angle (VASE,manufactured by J. A. Woollam Co., Inc.). The results thereof are shownin Table 3. Further, by a nanoindentation test, hardness of eachforegoing coated film was measured with a SA-2 nanoindenter instrument(manufactured by Toyo Corporation). The results thereof are also shownin Table 3.

TABLE 3 Solution for forming optical under- Under- Raw property Hard-layer layer material (193 nm) ness film film polymer n-value k-value(GPa) Example SOL-1 UDL-1 Polymer 1 1.50 0.25 0.60 SOL-2 UDL-2 Polymer 21.57 0.20 0.65 SOL-3 UDL-3 Polymer 3 1.53 0.40 0.60 SOL-4 UDL-4 Polymer4 1.53 0.41 0.55 SOL-5 UDL-5 Polymer 5 1.55 0.50 0.60 SOL-6 UDL-6Polymer 6 1.55 0.49 0.65 SOL-7 UDL-7 Polymer 7 1.50 0.31 0.55 SOL-8UDL-8 Polymer 8 1.50 0.26 0.60 SOL-9 UDL-9 Polymer 9 1.55 0.30 0.65Comparative SOL-10 UDL-10 Polymer 10 1.50 0.22 0.45 Example SOL-11UDL-11 Polymer 11 1.50 0.21 0.40 SOL-12 UDL-12 Polymer 12 1.51 0.22 0.45

As shown in Table 3, the bottom resist layers of UDL-1 to UDL-12 have nvalues of refractive index about 1.5, and k values of refractive indexin the range of 0.20 to 0.50. Thus the bottom resist layers havesufficient antireflection effects as bottom resist layers for trilayerresist. The bottom resist layers have optimum refractive indexes (nvalues) and optimum extinction coefficients (k values) that providesufficient antireflection effects in particular when the bottom resistlayers have thicknesses of 200 nm or more.

In addition, the resist underlayer films formed by spin-coating have anexcellent filling-up property.

When comparisons were made between UDL-1 and UDL-10, between UDL-4 andUDL-11, and between UDL-8 and UDL-12, results of each hardness, i.e.,0.60 and 0.45, 0.55 and 0.40, and 0.60 and 0.45, were obtained. From theresults, it can be seen that those polymers containing a substituentgroup that has a double bond in a 5-membered or a 6-membered alicyclicstructure have a higher hardness and a more dense structure than thosepolymers not containing the said substituent group.

Moreover, from the comparison between UDL-7 and UDL-8, it can be seenthat UDL-8, having a higher mole ratio of the cyclohexene structure, hasa higher hardness, indicating that the substituent group having a doublebond contributes to improvement of the hardness of a coated film.

In addition, it can be seen that the k-value and the hardness can becontrolled by presence or not presence of an aldehyde compound shown bythe general formula (3).

Examples 1 to 9 and Comparative Examples 1 to 3 Pattern Etching Tests

Each of the resist underlayer film compositions (UDL-1 to UDL-12) wasapplied (spin-coated) onto a Si wafer substrate (diameter of 300 mm)formed with a SiO₂ film having film thickness of 200 nm, and then bakedat 250° C. for 60 seconds to obtain a resist underlayer film having filmthickness of 200 nm (Examples 1 to 9 and Comparative Examples 1 to 3). Aresist intermediate film composition containing a silicon atom (SOG-1)that was prepared by a conventional method was applied, and then bakedat 220° C. for 60 seconds to form a resist intermediate film having filmthickness of 35 nm; then a resist upper layer film composition (SLresist solution for ArF) was applied, and then baked at 105° C. for 60seconds to form a resist upper layer film having film thickness of 100nm. An immersion-top coat (TC-1) was applied onto the resist upper layerfilm thus obtained, and then baked at 90° C. for 60 seconds to form atop coat having film thickness of 50 nm. The upper layer resist wasprepared by dissolving a resin, an acid generator, and a basic compound,with the components and ratio thereof as shown in Table 4, into asolvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3MLimited), followed by filtering the thus obtained solution through a0.1-μm filter made of a fluorinated resin.

TABLE 4 Acid Basic generator compound Solvent Polymer (parts by (partsby (parts by No. (parts by mass) mass) mass) mass) SL resist ArFmonolayer resist PAG 1 Amine 1 PGMEA for ArF polymer 1 (6.6) (0.8)(2,500) (100)

PGMEA 2-methoxypropylacetate

A resin having a composition shown in Table 5, was dissolved into asolvent, followed by filtration by a filter made of fluororesin of a 0.1μm size, to prepare a immersion resist top coat (TC-1).

TABLE 5 Polymer Organic solvent (parts by mass) (parts by mass) TC-1 Topcoat polymer (100) diisoamyl ether (2700) 2-methyl-1-butanol (270) Topcoat polymer: the following structural formula

Weight-average molecular weight (Mw) = 8,800 Molecular-weightdistribution (Mw/Mn) = 1.69

Then, each of the samples thus obtained was exposed with changing theexposure dose by using an ArF immersion exposure instrument NSR-S610C(manufactured by Nikon Corporation; NA 1.30, σ 0.98/0.65, 35-degreedipole s-polarized illumination, 6% half tone phase-shift mask), bakedat 100° C. for 60 seconds (PEB), and then developed by an aqueoussolution of 2.38% by mass of tetramethyl ammonium hydroxide (TMAH) for30 seconds to obtain a positive type line-and-space pattern with theresist line width ranging from 50 nm to 30 nm and with 100 nm pitch.

Then, by using an etching equipment Telius (manufactured by TokyoElectron Ltd.), the silicon-containing intermediate film was processedby dry etching using the resist pattern as a mask; thereafter, theunderlayer film was processed by using the silicon-containingintermediate film as a mask, and then the SiO₂ film was processed byusing the underlayer film as a mask. The results are shown in Table 6.

The etching was done under the conditions shown below.

Transfer Condition of a Resist Pattern to an SOG Film:

Chamber pressure: 10.0 Pa

RF power: 1,500 W

CF₄ gas flow rate: 15 sccm

O₂ gas flow rate: 75 sccm

Treating time: 15 sec

Transfer Condition of the SOG Film to an Underlayer Film

Chamber pressure: 2.0 Pa

RF power: 500 W

Ar gas flow rate: 75 sccm

O₂ gas flow rate: 45 sccm

Treating time: 120 sec

Transfer Condition to an SiO₂ Film

Chamber pressure: 2.0 Pa

RF power: 2,200 W

C₅F₁₂ gas flow rate: 20 sccm

C₂F₆ gas flow rate: 10 sccm

Ar gas flow rate: 300 sccm

O₂ gas flow rate: 60 sccm

Treating time: 90 sec

Cross section of the pattern was observed by an electron microscope(S-4700, manufactured by Hitachi Ltd.) and the forms were compared. Theresults are summarized in Table 6.

TABLE 6 Mimimum- pattern size without causing the pattern Profile afterProfile after deformation Upper- etching for etching for Profile afterafter Under- layer Pattern transfer to transfer to etching for theetching layer resist profile after intermediate underlayer transfer tofor transfer to film film development film film substrate the substrateExample 1 UDL-1 SL Perpendicular Perpendicular PerpendicularPerpendicular 35 nm resist for ArF Example 2 UDL-2 SL PerpendicularPerpendicular Perpendicular Perpendicular 33 nm resist for ArF Example 3UDL-3 SL Perpendicular Perpendicular Perpendicular Perpendicular 35 nmresist for ArF Example 4 UDL-4 SL Perpendicular PerpendicularPerpendicular Perpendicular 36 nm resist for ArF Example 5 UDL-5 SLPerpendicular Perpendicular Perpendicular Perpendicular 35 nm resist forArF Example 6 UDL-6 SL Perpendicular Perpendicular PerpendicularPerpendicular 32 nm resist for ArF Example 7 UDL-7 SL PerpendicularPerpendicular Perpendicular Perpendicular 35 nm resist for ArF Example 8UDL-8 SL Perpendicular Perpendicular Perpendicular Perpendicular 35 nmresist for ArF Example 9 UDL-9 SL Perpendicular PerpendicularPerpendicular Perpendicular 35 nm resist for ArF Comparative UDL-10 SLPerpendicular Perpendicular Perpendicular Perpendicular 39 nm Example1resist for ArF Comparative UDL-11 SL Perpendicular PerpendicularPerpendicular Perpendicular 41 nm Example2 resist for ArF ComparativeUDL-12 SL Perpendicular Perpendicular Perpendicular Perpendicular 40 nmExample3 resist for ArF

As can be seen in Table 3, the underlayer film of the present inventionhas the refractive index qualified as the underlayer film of an actualuse in the trilayer resist for an immersion lithography.

In addition, as shown in Table 6, the resist form after development, theform after etching by oxygen, and the form of the underlayer film afteretching of the substrate were excellent. A pattern size after substratetransference changed in accordance with the resist line width formed bythe exposure. As a result, pattern wiggling was formed at line width ofabout 40 nm in a material whose hardness was less than 0.50 GPa. On theother hand, it was found that wiggling was not formed until the patternsize reached 36 nm or lower when the underlayer film having hardness of0.55 GPa or more was used.

The present invention is not limited to the above-described embodiment.The above-described embodiment is a mere example, and those having thesubstantially same structure as that described in the appended claimsand providing the similar action and effects are included in the scopeof the present invention.

What is claimed is:
 1. A resist underlayer film composition, wherein theresist underlayer film composition is used for forming a resistunderlayer film to be formed in an underlayer of an upper layer film andto be used for photolithography using a multilayer resist method and thecomposition contains a polymer represented by general formula (4-1) or(4-2) and an acid generator:

wherein: R¹ to R⁸ independently represent a hydrogen atom, a halogenatom, a hydroxyl group, an isocyanato group, a glycidyloxy group, acarboxyl group, an amino group, an alkoxyl group having 1 to 30 carbonatoms, an alkoxy carbonyl group having 1 to 30 carbon atoms, analkanoyloxy group having 1 to 30 carbon atoms, or anoptionally-substituted saturated or unsaturated organic group having 1to 30 carbon atoms, wherein two substituent groups arbitrarily selectedfrom each of R¹ to R⁴ or R⁵ to R⁸ may be bonded to form a cyclicsubstituent group within a molecule; X represents a monovalent organicgroup with up to 30 carbon atoms and containing one or more of a5-membered or a 6-membered aliphatic cyclic structure that contains adouble bond; Y is different from X and represents a hydrogen atom or anoptionally-substituted monovalent organic group having 1 to 30 carbonatoms; a, b, c, and d represent a ratio of each unit to a total numberof repeating units and satisfy 0≦d<c<a+b<1 and a+b+c+d=1; and *indicates a bonding position.
 2. The resist underlayer film compositionaccording to claim 1, wherein the resist underlayer film compositionfurther contains any one or more of a crosslinking agent and an organicsolvent.
 3. A patterning process on a body to be processed, wherein: aresist underlayer film is formed on the body to be processed by usingthe resist underlayer film composition according to claim 2, a resistintermediate film is formed on the resist underlayer film by using aresist intermediate film composition containing a silicon atom, a resistupper layer film is formed on the resist intermediate film by using aresist upper layer film composition of a photoresist composition, acircuit pattern is formed in the resist upper layer film, the resistintermediate film is etched by using the resist upper layer film formedwith the pattern as a mask, the resist underlayer film is etched byusing the resist intermediate film formed with the pattern as a mask,and the body to be processed is etched by using the resist underlayerfilm formed with the pattern as a mask, whereby a pattern is formed onthe body to be processed.
 4. A patterning process on a body to beprocessed, wherein: a resist underlayer film is formed on a body to beprocessed by using the resist underlayer film composition according toclaim 2, a resist intermediate film is formed on the resist underlayerfilm by using a resist intermediate film composition containing asilicon atom, an organic antireflective film (BARC) is formed on theresist intermediate film, a resist upper layer film is formed on theBARC by using a resist upper layer film composition of a photoresistcomposition thereby forming a four-layer resist film, a circuit patternis formed in the resist upper layer film, the BARC and the resistintermediate film are etched by using the resist upperlayer film formedwith the pattern as a mask, the resist underlayer film is etched byusing the resist intermediate film formed with the pattern as a mask,and the body to be processed is etched by using the resist underlayerfilm formed with the pattern as a mask, whereby a pattern is formed onthe body to be processed.
 5. A patterning process on a body to beprocessed, wherein: a resist underlayer film is formed on a body to beprocessed by using the resist underlayer film composition according toclaim 2, an intermediate film of an inorganic hard mask, selected fromany of a silicon oxide film, a silicon nitride film, a silicon oxidenitride film, and an amorphous silicon film, is formed on the resistunderlayer film, a resist upper layer film is formed on the intermediatefilm of the inorganic hard mask by using a resist upper layer filmcomposition of a photoresist composition, a circuit pattern is formed inthe resist upper layer film, the intermediate film of the inorganic hardmask is etched by using the resist upperlayer film formed with thepattern as a mask, the resist underlayer film is etched by using theintermediate film of the inorganic hard mask formed with the pattern asa mask, and the body to be processed is etched by using the resistunderlayer film formed with the pattern as a mask, whereby a pattern isformed on the body to be processed.
 6. A patterning process on a body tobe processed, wherein: a resist underlayer film is formed on a body tobe processed by using the resist underlayer film composition accordingto claim 2, an intermediate film of an inorganic hard mask, selectedfrom any of a silicon oxide film, a silicon nitride film, a siliconoxide nitride film, and an amorphous silicon film, is formed on theresist underlayer film, an organic antireflective film (BARC) is formedon the intermediate film of the inorganic hard mask, a resist upperlayer film is formed on the BARC by using a resist upper layer filmcomposition of a photoresist composition thereby forming a four-layerresist film, a circuit pattern is formed in the resist upper layer film,the BARC and the intermediate film of the inorganic hard mask are etchedby using the resist upperlayer film formed with the pattern as a mask,the resist underlayer film is etched by using the intermediate film ofthe inorganic hard mask formed with the pattern as a mask, and the bodyto be processed is etched by using the resist underlayer film formedwith the pattern as a mask, whereby a pattern is formed on the body tobe processed.
 7. A patterning process on a body to be processed,wherein: a resist underlayer film is formed on the body to be processedby using the resist underlayer film composition according to claim 1, aresist intermediate film is formed on the resist underlayer film byusing a resist intermediate film composition containing a silicon atom,a resist upper layer film is formed on the resist intermediate film byusing a resist upper layer film composition of a photoresistcomposition, a circuit pattern is formed in the resist upper layer film,the resist intermediate film is etched by using the resist upper layerfilm formed with the pattern as a mask, the resist underlayer film isetched by using the resist intermediate film formed with the pattern asa mask, and the body to be processed is etched by using the resistunderlayer film formed with the pattern as a mask, whereby a pattern isformed on the body to be processed.
 8. The patterning process accordingto claim 7, wherein the circuit pattern is formed in the resist upperlayer film by a method selected from the group consisting of aphotolithography method with a wavelength range between 10 nm or longerand 300 nm or shorter, a direct drawing method by an electron beam, anda nanoimprinting method, or a combination thereof.
 9. The patterningprocess according to claim 7, wherein a development method in thepatterning process is an alkaline development or a development by anorganic solvent.
 10. The patterning process according to claim 7,wherein: the body to be processed comprises, on a substrate of asemiconductor device, a film selected from the group consisting of ametal film, a metal carbide film, a metal oxide film, a metal nitridefilm, and a metal oxide nitride film.
 11. The patterning processaccording to claim 10, wherein the metal is selected from the groupconsisting of silicon, titanium, tungsten, hafnium, zirconium, chromium,germanium, aluminum, copper, iron, and an alloy thereof.
 12. Apatterning process on a body to be processed, wherein: a resistunderlayer film is formed on the body to be processed by using theresist underlayer film composition according to claim 1, a resistintermediate film is formed on the resist underlayer film by using aresist intermediate film composition containing a silicon atom, anorganic antireflective film (BARC) is formed on the resist intermediatefilm, a resist upper layer film is formed on the BARC by using a resistupper layer film composition of a photoresist composition therebyforming a four-layer resist film, a circuit pattern is formed in theresist upper layer film, the BARC and the resist intermediate film areetched by using the resist upperlayer film formed with the pattern as amask, the resist underlayer film is etched by using the resistintermediate film formed with the pattern as a mask, and the body to beprocessed is etched by using the resist underlayer film formed with thepattern as a mask, whereby a pattern is formed on the body to beprocessed.
 13. A patterning process on a body to be processed, wherein:a resist underlayer film is formed on the body to be processed by usingthe resist underlayer film composition according to claim 1, anintermediate film of an inorganic hard mask, selected from any of asilicon oxide film, a silicon nitride film, a silicon oxide nitridefilm, and an amorphous silicon film, is formed on the resist underlayerfilm, a resist upper layer film is formed on the intermediate film ofthe inorganic hard mask by using a resist upper layer film compositionof a photoresist composition, a circuit pattern is formed in the resistupper layer film, the intermediate film of the inorganic hard mask isetched by using the resist upperlayer film formed with the pattern as amask, the resist underlayer film is etched by using the intermediatefilm of the inorganic hard mask formed with the pattern as a mask, andthe body to be processed is etched by using the resist underlayer filmformed with the pattern as a mask, whereby a pattern is formed on thebody to be processed.
 14. The patterning process according to claim 13,wherein the intermediate film of the inorganic hard mask is formed by aCVD method or an ALD method.
 15. A patterning process on a body to beprocessed, wherein: a resist underlayer film is formed on the body to beprocessed by using the resist underlayer film composition according toclaim 1, an intermediate film of an inorganic hard mask, selected fromany of a silicon oxide film, a silicon nitride film, a silicon oxidenitride film, and an amorphous silicon film, is formed on the resistunderlayer film, an organic antireflective film (BARC) is formed on theintermediate film of the inorganic hard mask, a resist upper layer filmis formed on the BARC by using a resist upper layer film composition ofa photoresist composition thereby forming a four-layer resist film, acircuit pattern is formed in the resist upper layer film, the BARC andthe intermediate film of the inorganic hard mask are etched by using theresist upperlayer film formed with the pattern as a mask, the resistunderlayer film is etched by using the intermediate film of theinorganic hard mask formed with the pattern as a mask, and the body tobe processed is etched by using the resist underlayer film formed withthe pattern as a mask, whereby a pattern is formed on the body to beprocessed.
 16. The patterning process according to claim 15, wherein theintermediate film of the inorganic hard mask is formed by a CVD methodor an ALD method.
 17. The patterning process according to claim 16,wherein the circuit pattern in the resist upper layer film is formed bya method selected from the group consisting of a photolithography methodwith a wavelength range between 10 nm or longer and 300 nm or shorter, adirect drawing method by an electron beam, and a nanoimprinting method,or a combination thereof.
 18. The patterning process according to claim17, wherein a development method in the patterning process is analkaline development or a development by an organic solvent.
 19. Thepatterning process according to claim 18, wherein: the body to beprocessed comprises, on a substrate of a semiconductor device, a filmselected from the group consisting of a metal film, a metal carbidefilm, a metal oxide film, a metal nitride film, and a metal oxidenitride film.
 20. The patterning process according to claim 19, whereinthe metal is selected from the group consisting of silicon, titanium,tungsten, hafnium, zirconium, chromium, germanium, aluminum, copper,iron, and an alloy thereof.